Melamine foam has a very fine pore reticulated structure, and is typically hygroscopic and hydrophilic. Under high humidity conditions, the foam may absorb moisture, and some degree of dimensional change can take place. In environments where the product is exposed to water and water based fluids, it readily absorbs these fluids. Melamine foam also contains residual retained formaldehyde, which can be released over time, especially in the presence of liquid water or high atmospheric humidity.
Melamine foams are highly temperature resistant, and can typically withstand temperatures up to 375° F. in continuous service. The product produces extremely low smoke and flame levels and is suitable for use in architectural and aerospace type applications. The byproducts of combustion have very low toxicity.
Unfortunately, the typically hygroscopic nature of many prior art melamine foams makes them unsuitable for use in a number of applications, such as for example pressurized aircraft applications where significant condensation occurs at elevated altitudes. This becomes particularly problematic when considering the material for use as fuselage insulation. Similarly, the residual formaldehyde is a negative attribute that causes the product to be unsuitable in many applications, such as automobile interiors.
There is thus still a need for a melamine foam product that is hydrophobic rather than hydrophilic, and exhibits reduced formaldehyde release.